Fabrication of a high resolution biological molecule detection device with aluminum electrical conductors

Abstract

The present invention relates to a method of manufacturing a detection device which involves providing a substrate having a layer of aluminum and a first layer of photosensitive material. Next, the substrate is subjected to a first level photolithography treatment to produce an aluminum electrical conductor containing conductive fingers with spaces between them. Finally, biological probes are attached to the conductive fingers under conditions effective to form a gap between the biological probes on the spaced apart conductive fingers. As a result, a target molecule, if present in a sample, can bind to a pair of the biological probes on the spaced apart conductive fingers to bridge the gap between the biological probes, allowing detection of the target molecule.

1 . A method of manufacturing a detection device, said method comprising: 
 providing a substrate having a layer of aluminum between a first layer of photosensitive material and a base layer;    subjecting the substrate to a first level photolithography treatment to produce an aluminum electrical conductor comprising conductive fingers with spaces between them;    covering the spaces between the conductive fingers with an electrical insulator material; and    attaching biological probes to the conductive fingers under conditions effective to form a gap between the biological probes on the spaced apart conductive fingers, whereby a target molecule, if present in a sample, can bind to a pair of the biological probes on the spaced apart conductive fingers to bridge the gap between the biological probes, allowing detection of the target molecule.    
     
     
         2 . A method according to  claim 1 , wherein the biological probes are oligonucleotide probes and the target molecule is a nucleic acid molecule.  
     
     
         3 . A method according to  claim 1 , wherein the biological probes are proteins or antibodies.  
     
     
         4 . A method according to  claim 1 , wherein said substrate further comprises a first layer of electrical insulator material between the base layer and the layer of aluminum.  
     
     
         5 . A method according to  claim 4 , wherein said providing a substrate comprises: 
 depositing the first layer of electrical insulator material on one side of the base layer;    depositing the layer of aluminum on the first layer of electrical insulator material; and    coating the first layer of photosensitive material onto the layer of aluminum.    
     
     
         6 . A method according to  claim 4 , wherein said subjecting the substrate to first level photolithography treatment comprises: 
 exposing certain portions of the first layer of photosensitive material to ultraviolet light through a first photomask;    developing and baking the first layer of photosensitive material leaving portions of the layer of aluminum uncovered;    removing the uncovered portions of the layer of aluminum from said substrate, leaving portions of the first layer of electrical insulator material uncovered; and    removing the photosensitive material remaining on the layer of aluminum.    
     
     
         7 . A method according to  claim 6 , wherein said method is carried out such that the portions of the first layer of photosensitive material that were exposed to ultraviolet light are removed.  
     
     
         8 . A method according to  claim 6 , wherein said method is carried out such that the portions of the first layer of photosensitive material that were not exposed to ultraviolet light are removed.  
     
     
         9 . A method according to  claim 1 , wherein said covering the spaces between the conductive fingers with an electrical insulator material comprises: 
 depositing a diamond film on said substrate after said subjecting the substrate to a first level photolithography treatment;    coating a second layer of photosensitive material onto the diamond film; and    subjecting the substrate to a second level photolithography treatment to cover the spaces between the conductor fingers with the diamond film.    
     
     
         10 . A method according to  claim 9 , wherein said subjecting the substrate to a second level photolithography treatment comprises: 
 exposing the second layer of photosensitive material to ultraviolet light through a second photomask;    developing and baking the second layer of photosensitive material, leaving portions of the diamond film uncovered;    removing the uncovered portions of the diamond film from said layer of aluminum, wherein said exposing, said developing and baking, and said removing the uncovered portions of the diamond film during said second level photolithography treatment are carried out such that only portions of the diamond film aligned with the conductive fingers will be removed, leaving portions of the second layer of photosensitive material on the substrate; and    removing the second layer of photosensitive material remaining on the diamond film.    
     
     
         11 . A method according to  claim 10 , wherein said method is carried out such that the portions of the second layer of photosensitive material that were exposed to ultraviolet light are removed.  
     
     
         12 . A method according to  claim 10 , wherein said method is carried out such that the portions of the second layer of photosensitive material that were not exposed to ultraviolet light are removed.  
     
     
         13 . A method according to  claim 1 , wherein the electrical insulator material covering the spaces between the conductive fingers is a diamond film.  
     
     
         14 . A method of manufacturing a detection device, said method comprising: 
 providing a substrate having a base layer,    depositing a first layer of electrical insulator material on one side of the base layer;    depositing a layer of aluminum on the first layer of electrical insulator material;    coating a first layer of photosensitive material onto the layer of aluminum;    exposing certain portions of the first layer of photosensitive material to ultraviolet light through a first photomask;    developing and baking the first layer of photosensitive material, leaving portions of the layer of aluminum uncovered;    removing the uncovered portions of the layer of aluminum from said substrate, leaving portions of the first layer of electrical insulator material uncovered;    removing the photosensitive material remaining on the layer of aluminum;    depositing a diamond film on said substrate;    coating a second layer of photosensitive material onto the diamond film;    exposing the second layer of photosensitive material to ultraviolet light through a second photomask;    developing and baking the second layer of photosensitive material, leaving portions of the diamond film uncovered;    removing the uncovered portions of the diamond film from said layer of aluminum, wherein said exposing the second layer of photosensitive material, said developing and baking the second layer of photosensitive material, and said removing the uncovered portions of the diamond film are carried out such that only portions of the diamond film aligned with the conductive fingers will be removed, leaving portions of the second layer of photosensitive material on the substrate; and    removing the second layer of photosensitive material remaining on the diamond film; and    attaching biological probes to the conductive fingers under conditions effective to form a gap between the biological probes on the spaced apart conductive fingers, whereby a target molecule, if present in a sample, can bind to a pair of the biological probes on the spaced apart conductive fingers to bridge the gap between the biological probes, allowing detection of the target molecule.    
     
     
         15 . A method according to  claim 14 , wherein the biological probes are oligonucleotide probes and the target molecule is a nucleic acid molecule.  
     
     
         16 . A method according to  claim 14 , wherein the biological probes are proteins or antibodies.  
     
     
         17 . A method according to  claim 14 , wherein said method is carried out such that the portions of the first layer of photosensitive material that were exposed to ultraviolet light are removed.  
     
     
         18 . A method according to  claim 14 , wherein said method is carried out such that the portions of the first layer of photosensitive material that were not exposed to ultraviolet light are removed.  
     
     
         19 . A method according to  claim 14 , wherein said method is carried out such that the portions of the second layer of photosensitive material that were exposed to ultraviolet light are removed.  
     
     
         20 . A method according to  claim 14 , wherein said method is carried out such that the portions of the second layer of photosensitive material that were not exposed to ultraviolet light are removed.  
     
     
         21 . A method of manufacturing a detection device, said method comprising: 
 providing a substrate having an aluminum electrical conductor comprising a plurality of coplanar conductive fingers with spaces between them, wherein the spaces are covered with an electrical insulator material; and    attaching biological probes to the conductive fingers under conditions effective to form a gap between probes on the spaced apart, coplanar, conductive fingers, whereby a target molecule, if present in a sample, can bind to a pair of the biological probes on the spaced apart, coplanar, conductive fingers to bridge the gap between the biological probes, allowing detection of the target molecule.    
     
     
         22 . A method according to  claim 21 , wherein the biological probes are oligonucleotide probes and the target molecule is a nucleic acid molecule.  
     
     
         23 . A method according to  claim 21 , wherein the biological probes are proteins or antibodies.  
     
     
         24 . A method according to  claim 21 , wherein the electrical insulator material covering the spaces between the conductive fingers is a diamond film.  
     
     
         25 . A method of manufacturing a detection device, said method comprising: 
 providing a substrate having a layer of aluminum and a first layer of photosensitive material;    subjecting the substrate to a first level photolithography treatment to produce an aluminum electrical conductor comprising conductive fingers with spaces between them; and    attaching biological probes to the conductive fingers under conditions effective to form a gap between the biological probes on the spaced apart conductive fingers, whereby a target molecule, if present in a sample, can bind to a pair of the biological probes on the spaced apart conductive fingers to bridge the gap between the biological probes, allowing detection of the target molecule.    
     
     
         26 . A method according to  claim 25 , wherein said substrate further comprises a base layer wherein said layer of aluminum is between said first layer of photosensitive material and said base layer.  
     
     
         27 . A method according to  claim 25 , further comprising: 
 covering the spaces between the conductive fingers with an electrical insulator material, prior to said attaching biological probes and after said subjecting the substrate to a first level photolithography.    
     
     
         28 . A method according to  claim 27 , wherein the electrical insulator material covering the spaces between the conductive fingers is a diamond film.  
     
     
         29 . A method according to  claim 25 , wherein the biological probes are oligonucleotide probes and the target molecule is a nucleic acid molecule.  
     
     
         30 . A method according to  claim 25 , wherein the biological probes are proteins or antibodies.